1. Field of the Invention
The present invention relates generally to disk drives, and in particular to a disk drive including an actuator with a pivot shaft and a disk drive base with an actuator support section for attachment of the pivot shaft and a seal.
2. Description of the Prior Art
The typical hard disk drive includes a head disk assembly (HDA) and a printed circuit board assembly (PCBA) attached to a disk drive base of the HDA. The head disk assembly includes at least one disk (such as a magnetic disk), a spindle motor for rotating the disk, and a head stack assembly (HSA). The printed circuit board assembly includes a servo control system in the form of a disk controller for generating servo control signals. The head stack assembly includes at least one transducer head, typically several, for reading and writing data from and to the disk. The head stack assembly is controllably positioned in response to the generated servo control signals from the disk controller. In so doing, the attached heads are moved relative to tracks disposed upon the disk.
The head stack assembly includes an actuator assembly, at least one head gimbal assembly, and a flex circuit assembly. A conventional “rotary” or “swing-type” actuator assembly typically includes a rotary actuator having an actuator body. The actuator body has a bore and a pivot bearing cartridge engaged within the bore to facilitate rotational movement of the actuator assembly between limited positions about an axis of rotation. A coil support extends from one side of the actuator body. An actuator coil is supported by the coil support and is configured to interact with one or more permanent magnetic elements, typically a pair, to form a voice coil motor. One or more actuator arms extend from an opposite side of the actuator body. Each head gimbal assembly includes a transducer head, typically a magneto-resistive (“MR”) head, which is distally attached to each of the actuator arms. Each magnetic disk includes opposing disk surfaces. Data may be recorded along data annular regions on a single disk surface or both. As such, the head stack assembly may be pivoted such that each transducer head is disposed adjacent to the various data annular regions from adjacent to the outer diameter to the inner diameter of each disk.
The spindle motor includes a spindle motor magnet and a stator. The magnet may be attached to an underside of the spindle motor hub. The stator may be disposed at the disk drive base and may be integrated therewith.
The printed circuit board assembly is attached to an underside of the disk drive base. A base insulator may be disposed between the disk drive base and the printed circuit board assembly for electrically insulating the various electrical components of the printed circuit board assembly from the disk drive base. In some applications a PCBA shield may be disposed over the printed circuit board assembly with the printed circuit board assembly between the PCBA shield and the disk drive base.
As mentioned above the head stack assembly includes the pivot bearing cartridge. The pivot bearing cartridge includes a pivot shaft. The pivot shaft includes a shaft body and a shaft threaded end. The shaft threaded end is engaged in a threaded hole formed in the disk drive base. A seal may be disposed over the threaded hole for sealing the disk drive base.
A topic of concern is the attachment of such threaded end of the pivot shaft into the threaded hole in the disk drive base. As weight and sizing specifications are tightened, the relative thickness of the disk drive base is reduced. Such reduction results in less vertical surface in the threaded hole of the disk drive base to engage the threaded end of the pivot shaft.
Accordingly, there is a need in the art for an improved pivot bearing cartridge attachment arrangement and disk drive base seal configuration in comparison to the prior art.